A template

Exp = <( <Exp> )>

results in a recursive pretty-print rule

prettyprint-Exp :
  a -> [ H(
           [SOpt(HS(), "0")]
         , [S("( "), a63, S(" )")]
         )
       ]
where a63 := <pp-one-Z(prettyprint-Exp)> a

This will result in a looping pretty-printer. Of course, the template is wrong, but it should never lead to a looping pretty-printer.

Submitted by Guido Wachsmuth on 9 October 2013 at 13:39